ANALYSIS OF METHODS FOR INCREASING THE SURVIVABILITY OF SMALL ARMS AND CANNON BARRELS BY THE APPLICATION OF CHROME COATINGS

Abstract

This paper is an analysis of modern chrome coating technologies for the barrels of small arms and cannons. Barrel survivability refers to the ability of a weapon system to fire a certain number of rounds without significant deterioration in ballistic characteristics. There are various methods to provide the necessary survivability of the barrels, both technological and constructive. This paper will consider technological methods, in particular chroming technologies. The objects of the research are various methods of chromium coating: electrolytic, cylindrical magnetron sputtering, galvanic honing, cathode-mechanical chromium plating, and thermodiffusion saturation by chromium. Electrolytic chrome plating in baths is the most common method, however it has significant drawbacks - toxic waste, difficulty in providing uniformity and integrity of plating, hydrogen release during plating, the need for subsequent heat treatment of the barrel. Coating barrels with cylindrical magnetron sputtering is one of the least studied methods, but from the available materials we can note the reduced toxicity and the absence of hydrogenation of the barrel and the plating. Nevertheless, the adhesion of the coating material and the barrel should be investigated. Analysis of the thermodiffusion chrome saturation method is also a promising method. However, a reduction in temperature during the coating process and subsequent normalization of the coating is necessary. This method is currently being investigated in the "Special purpose product technology" laboratory at the Azerbaijan Technical University. As a result of the research, the most prospective methods can be considered galvanic honing, the cathodic-mechanical method and thermodiffusion chrome saturation. The advantages of these methods are increased productivity and quality of the plating surface. In addition to the prospective chrome plating methods, the paper also noted questions for which the answers remain open. Keywords: barrel, coating, chromium plating, wear, electroplating, magnetron sputtering, diffusion.